You would think it would be a simple process. I do on occasion just use Photoshop to extend the canvas and add the lines manually. Having worked on hundreds of these 9patch files though, it's an incredibly repetitive process especially when many of these buttons need the same exact measurements. Being off by even one pixel will make your button look wrong. Then when you put it in your app, you realize that you need to make some adjustments. So you'll have to repeat changes to the 4 or 5 different states you have per button. If you have to resize the graphic, you might as well just do the 9patch lines from scratch. Then consider all the iterations you'd have to go through again for each different texture density you are developing for. You can't just scale the image because you need exactly 1px wide black lines.

Using a tool is nice for live previews and guides and some even generate multiple densities for you automatically. However, I haven't found a free software that really does what I want. The draw9patch tool distributed with the Android SDK has an incredibly awful interface and unresponsive controls. It's just very fiddly. Nine-patch editor is close, but has a bug with graphics that have black borders and isn't being developed anymore.

DranikProgrammer, I believe you're referring to the Simple nine-patch generator from Android Asset Studio. That works very well and has some nice features, but it doesn't look like you can edit an existing 9patch file with it. I'd consider that a deal breaker. Android Studio has 9patch editing built into the IDE. I haven't been able to test that out yet.

To answer some of my own issues, short of making my own program as I mentioned, I created several actions in Photoshop to do common operations (clearing 9patch values, copying 9patch from one image to another, etc.). The nice thing about that is you can you run them as batch operations. See File >> Automate >> Batch in Photoshop. My actions aren't production ready though. I'm constantly tweaking them to the particular project I'm working on. I'd share them some day if there is any interest in them.

Just wanted to say that you did an amazing job with this! I'd seen your skin composer in the past but was always slightly unsure how to use it. Now that I'm actually starting to work on skin stuff for my project I took another look at your program and realized how easy it was. Having examples in the welcome screen made it much easier for me to figure out how to use it. Pretty much every feature I imagined needing was already provided and seems intuitive. I really hope you continue to develop this and make other programs like it!

Thanks for your comments! Updates to skin composer have slowed down, however I still plan to maintain the project with any changes tp LibGDX's skin implimentation. If you have an issues, don't hesitate to post them on Github.

While composing my first own skin, I stumbled across the problem that often a padding was needed.

The button text needs padding, and also the list text and the list in the background. I did not find a way to set such a padding. Did I miss something? I wonder because also the window title position is not changeable, but it is perfectly fitting in the skins you provided.

Changing the table's padding programmatically in my game is of course possible. I just wanted to know if there is another way to go.